Control system.



A. J. HALL.

CONTROL SYSTEM.

APPLICATION men OCT. 23. m3.

Patented June 1 2, 1917.

2 SHEETS-SHEET l.

6 7 62 37 63 529 J6 5 /2 WITNESSES INVENTOR if a ATTORNEY A. J. HALL.CONTROL SYSTEM. APPLICATION FILED OCT. 23. 1913.

Patented June 12,1917.

2 SHEETS-SHEET}.

NVE TOR W I) WITNESSES: My

ATTORNEY ARTHUR .1. HALL, or WILKINSBURG, PENNSYLVANIA, ASSIGNOR ToWESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OFPENNSYLVANIA.

CONTROL SYSTEM.

Specification of Letters latent.

Patented June 12, 1917.

Application filed October 23, 1913. Serial No. 796,867.

invented a new and useful Improvement in Control Systems, of which thefollowing is a specification.

My invention relates to systems and apparatus for controlling electricmotors, and it has special reference to power-actuated drum controllersand automatic systems embodying the same.

One object of my invention is to provlde a relatively simple and compactmechanism for actuating controllers of the drum type that shall beadapted to replace the usual cover and motormens handles of presentmanually operated railway controllers, and the operation of which isgoverned by a small master controller and by electro-responsive devicesdependent upon predetermined circuit conditions.

Another object of my invention is to provide a controller actuatingdevice of the character above indicated which shall be so constructedand arranged as to permit of its operation and use, either singly or inmultiple with others, for automatically controlling the operation ofeither single cars or trains composed of any number of cars.

Another object of my invention is to provide means for automaticallyefi'ecting stepby-step movement of the controller drum, which meansshall be dependent in its operation upon the current traversing themotor circuit or upon some [other suitable condition of the system.

A still further object of my invention is to provide means responsive tocurrent con ditions of the motor circuit for automatically maintainingthe motor current during acceleration substantially constant and betweentwo predetermined values.

In a eo=pending application, Serial No. 724,063 filed October 5, 1912,by Norman W. Storer and myself, and assigned to the WestinghouseElectric & Manufacturing Company, a system of control embodying myinvention is fully shown and described, although the claims incorporatedtherein relate to the apparatus and system in matters entirely apartfrom the automatic features thereof which constitute my presentinvention and which are covered by the claims appended hereto.

Flgure 1 of the accompanying drawings is a plan view, with the'coverremoved, of a controller operating head which forms a part of myinvention. Fig. 2 is a view in side elevation and in section of theoperating head of Fig. 1 and the upper portion of a controller withwhich the head is associated. Figs. 3 and 4 are sectional detail views,on a larger scale, of the valves which form parts of the operating headshown in the other figures. Figs. 5 and 6 are respectively adiagrammatic view of the control circuits and a diagrammatic view of themotor circuits of,a system embodying my invention.

Referring to Figs. 1 to 4, inclusive, of the drawings, the structurehere shown comprises an operating head 1, a controller of the well knowntype having a casing 2, a main drum 3, a reversing drum 4, and suitablecontrol fingers associated with each drum.

The operating head 1 comprises a base plate 5, which constitutes thecover of the casing 2, a pair of cylinders 6 and 7, pis-.

cylinders 13 and 14, pistons 15 and 16, a

connecting rod 17 for the pistons 15 and 16 adapted to actuate thereverse drum 4, electromagnetically controlled valves 18 and 19 r forcontrolling the supply of compressed air to the cylinders 13 and 14, anda pair of auxiliary or control drums 20 and 21 which are respectivelycoupled to the drums 3 and 4 of the controller and are provided withsuitable contact fingers. The cylinders 6, 7, 13 and 14 may form asingle casting or may be separately secured to the base plate 5 uponwhich they are mounted, and the cylinder heads are preferably formedintegral with the .valve casings with which they are associated.

A yoke 22 is mounted on the cylinder casting and is provided withbearings 23 and 24 in which a shaft 25 of the auxiliary drum 20 isrotatively supported. Another yoke 26 is secured to the cylinder castingand is provided with bearings 27 and 28 in which a shaft 29 of theauxiliary drum 21 is rotatively mounted.

The shafts 25 and 29 are respectively in substantial alinement withshafts 30 and 31 of the drums 3 and 4, to which they are operativelyconnected by couplings 32 and 33. The coupling 33 is provided with acrank projection 34 which is operatively connected to the piston rod 17by means of a link 35.

' The arrangement of parts is such that, when the actuating winding ofthe valves 18 and 19 are energized, compressed air is admitted throughthe said valves to the cylinders 13 and 14, and, when the said windingsare deenergized, the cylinders are open to the atmosphere and the airpressure within them is relieved.

The coupler 32 is provided with an annular toothed portion whichconstitutes a pinion and meshes with the teeth of the rack upon one sideof the connecting rod 10. The arrangement of parts is such that, whenfluid pressure is admitted through the valve 11 to the cylinder6 andfluid pressure is exhausted through the valve 12 from the cylinder 7,the pistons 8 and 9 and the connecting rod 10 are so actuated as toproduce rotative movement of the main drum 3 and the auxiliary orcontrol drum 20.

The electromagnetically actuated valves 11, 18 and 19 are substantiallyalike and each of them is constructed as shown in Fig. ,3 of thedrawings. The valve 12 is, however, constructed as shown in Fig. 4 ofthe drawings. Each of the valves 11, 18 and 19 comprises a casting 39having a vertically extending cylinder chamber, a pair of apertureddisks 37 and 38 having frustoconical valve seats located and spacedapart within the said chamber, a valve stem 42 having frusto-conicalplugs 40 and 41 adapted to engage said seats, and a magnet comprisin a,coil 43, a stationary core member 44, w ich forms a part of the casting39, and a movable core member or armature 45 which is secured to thevalve stem 42.

The cylindrical chamber in which the disks 37 and 38 are located isdivided thereby into an exhaust chamber 46 having an exhaust port 47, aninlet chamber 48 having an inlet port 49, and a pressure chamber 50 withwhich a passage 51 leading to the cylinder communicates. The lower endof the valve stem 42 is enlarged to form a frustoconical spring seat52', and a plug 53, which closes the lower end of the cylindricalchamber, is provided with an opposing conical projection 54, a helicalspring 55, which tends to force the plug 41 against its seat and toraise the plug 40 from its seat, being interposed between the members 52and 54. When the coil 43 is energized, the armature 45 is moveddownwardly to cause the plug haust passage is normally closed and itsadmission passage is normally open. It comprises a casting 56 having astepped cylindrical chamber which is divided into an exhaust chamber 57,a pressure chamber 58 and an admission chamber 59 by means of apertureddisks 60 and 61 having frustoconical valve seats.

A frusto-conical plug 62 for the exhaust passage cooperates with theseat in the disk 60 and is normally held in engagement therewith by aspring 63, while another plug 64 1s, by the same means, normallymaintained in a raised position and out of engagement with thecorresponding seat in the disk 61. The plugs 62 and 64' are carried by avalve stem 42 that is adapted to be actuated by an electromagnet slmilarto that shown in Figs. 2 and 3, the plug 62 being lowered away from itsseat when the electro-magnet is energized and the plug 64 being causedto engage its seat.

In view of the foregoing, it is evident that if the actuatingelectromagnets of the valves 18 and 19 are both deenergized, atmosphericpressure will exist in the cylinders 13 and 14, and, accordingly, nomovement of the pistons 15 and 16 or of the reverser and auxiliary drums4 and 21 will occur, while if one is energized and the other is deener'zed, the pistons, the connecting rod 17 an the link 35 will be movedaway from the valve, the electromagnet of which is energized. In order,therefore, to actuate the reverser drum 4 and the auxiliary control drum21, it is only necessary to energize the actuating winding of the valvein the opposite direction to that which it is desired to move thepistons 15 and 16.

Since the valves 11 and 12 are different in construction, that is, sincethe valve parts in the one are in inverse relation to those in theother, full pressure will normall exist in the cylinder 7, whilepressure will e exhausted from the cylinder 6 when the actuatin windingsof both magnets are deenergize and, therefore, the drum 3 and thecontrol drum 20 will be moved into or held in their off positions.

In order to advance the said drums, it is only necessary to energize theactuating windings of both the valves 11 and 12, thereby introducingfull pressure to the cylinder 6, and exhausting pressure from thecylinder 7. The drums may be stopped andheld indefinitely in anyposition by merely deenergizing the actuating winding of the valve 12while energy is supplied to the'winding oi the valve 11, or, in otherwords, by restoring full balanced pressure, in the cylinders 6 and 7. I

The auxiliary or control drum 20, as hereinafter pointed out, is adaptedto govern the switches 75 and 76, an accelerating resistor 77, a pair ofelectric motors having armatures A and A and field magnet windings F andF a control circuit resistor 78, the auxiliary orcontrol drum 20, thereversing auxiliary or control drum 21, limit switches 79 and 7 9'respectively, marked Lower limit and Upper limit, an overload triprelayswitch 80, a main master switch 81 and a reversing master switch82.

The ccntrol circuit resistor 78 is connected directly between the supplycircuit conductors 71 and 72, when a pair of switches 83 and 84 areclosed.

The master reverser 82 is adapted to occupy positions a: and y and themaster switch 81 is adapted to occupy an 011' position and a pluralityof motor-operating positions 1 to 8, corresponding to the variouspositions of the main control drum 3.

Assuming that the master reverser 82 is thrown to position a: and thatthe master switch 81 is moved into position 1, a circuit is establishedfrom an intermediate tap 85 in the resistor 78, to a conductor. 86,contact fingers 87 and 88, which are bridged by a contact member 89, aconductor 90, contact fingers 91 and 92 of the auxiliary reverser drum21 which, are bridged by a contact member 93, actuating coil 94 ofthevalve 18, a conductor 95, contact fingers 96 and 97, which arebridged by a contact member 98 of the master reverser 82, an emergencycutout switch 99, a conductor 100, contact fingers 101, which arebridged by a contact member 102, and a conductor marked -0 tosubstantially the middle point in the control resistor 78. 1

The coil 94 of the valve 18 being now energized, causes fluid pressureto be admitted to the cylinder 13, with the result that the reverserdrum 4 and the auxiliary drum 21 are moved to the position m. In thisposition, the finger 92 is disengaged from the contact member 93 and,consequently, the coil 94 is deenergized so that fluid pressure 1sreleased from the cylinder 13 in order that the reverser may be readyfor subsequent operation in the opposite direction.

A circuit is concurrently completed from the conductor 90, throughcontact fingers 103, whlch are bridged by a contact member 104 when thecontroller 20 occupies its off position, a conductor 105, a coil 106 ofthe line switch, the trip relay switch 80, a conductor 107, contactfingers 108 and 109, which are bridged by a contact member 110 of thecontrol reverser 21, the conductor 95, etc. to the conductor 0. The lineswitch is thus closed and a holding circuit is established for the coil106 from the conductor 90, through the interlocking contact membersmarked LS-in.

As soon as the line switch closes, a circuit is established fromconductor 90, through the interlocking contact members LSin-, upperlimit 79*, actuating coil 115 of the valve 11, and the conductor 107,etc. to the 0 conductor. By reason of the energization of the coil 115.of valve 11, fluid pressure is admitted to the cylinder 6. However, no

movement of the plstons 8 and 9 occurs at this time because balanced inthe cylinders 6 and A connection is concurrently established from theconductor 90 through contact fingers 111 and 112, which are bridged by acontact member 113 of the auxiliary drum 20, a conductor 114, lowerlimit 79, actuating coil 117 of the valve 12, and conductor 107, etc. tothe 0 conductor. Fluid pressure is consequently released from thecylinder 7, and the drums 3 and 20 are moved forward until the contactfinger 111 becomes disengaged from the member 113. This occurs as soonas control drum 20 occupies position 1. At this point in the operation,the coil 117 of the valve 12 is denergized, therepressures exist byrestoring balanced pressures in the cylinders 6 and 7 and holding thedrums 3' and 20 in position 1.

Upon the movement of the drum 3, a

motor circuit is established from conductor 71, through the circuitbreaker 73, canopy switch 74, a conductor 116, the line switch LS,contact fingers 118 and 119, which are bridged by a contact member 120of the controller 3, the accelerating resistor 77, one blade of thecut-out switch 76, a conductor 120, contact fingers 121 and 122, whichare bridged by a contact member 123 of the reverser, a conductor 124,actuating coils 125 and 125 of the upper limit 79 and lower limit 79,armature A actuating coil 126 of the overload trip -relay switch 80, aconductor 127, contact fingers 128 and 129, which are bridged by acontact member 130, a conductor 131, field magnet winding F a conductor132, contact fingers 133 and 134,

which are bridged by a contact member 135, the other blade of the motorcut-out switch 76, and one blade of the cut-out switch 75,

- out switch 75 and a conductor 151 to the opact when a predeterminedgreater current posite line conductor 72.

The motors are thus connected in series relation, with the resistor 77and the energizing coils of both limit switches 79 and 7 9 included incircuit therewith. By reason of the com letion of the main motorcircuit, just recited, energy is supplied to the driving motors and theyare accordingly started into operation and are accelerated up to a speedcorresponding to the first position of the controller.

The acceleration of the motors will not progress so long as the masterswitch 81 remains in position 1, but if the master switch is movedsuccessively through its positions 2, 3 and 4, the coil 117 of the valve12 is alternately energized and deenergized, and the drums 3 and 20 willmove forward through the corresponding positions stepby-step, butdependent upon the action of the lower limit,79. Thus, the resistanceof. the motor circuit is gradually eliminated, thereby causing themotors to accelerate in speed.

The lower limit coll 125 1s so designed as to lift the switch 79 whenthe motor current exceeds a predetermined amount in accordance withcustomary practice, while the upper limit coil 125 is only adapted totraverses the motor circuit. When the motor current raises the lowerlimit 9, further progression of the controller is prevented because ofthe interruption of the energizing circuit of coil 117 of valve 12 whichcauses the admission of pressure to cylinder 7 and holds the controllerdrum at rest. As soon as the current falls and permits the lower limit79 to close, coil 117, is again energized and the valve 12 exhaustscylinder 7 and allows the piston 8 to advance the controller to its nextstep.

If, however, the motor current becomes excessive" and greater than thevalue for which the upper limit 79 is adjusted,'its switch is alsoraised. Thus, coil 115 of valve 11 is deenergized and cylinder 6 isopened to the atmosphere, thereby causing the controller to be movedbackward to cut in a portion of the accelerating resistance 77, byreason of the pressure in cylinder 7, already effected by the raising ofthe lower limit 79. When sufiicient resistance has been cut into circuitto reduce the motor current to a normal value, upper limit 79 falls, andbalanced pressures are restored. Subsequently, the operation may proceedin accordance with circuit conditions and the will of the operator.

It is evident, therefore, that the automatic operation is dependent uponthe action of two current relays or limit switches and the motor currentis maintained between two predetermined values, so that the accelerationis smooth and substantially uniform.

One of the predetermined values referred to is'the normal value of theaccelerating current, as maintained substantially constant through theaction of the lower limit, which functions in the usual manner ofautomatic limit switches.

The upper value is that to which the current is limited under abnormalaccelerating conditions by means of the upper limit. It is evident,therefore, that the accelerating current of the system set forth mayvary, and the limits of its variation are those pre scribed by the twolimit switches. The accelerating current, therefore, is permitted tovary between two predetermined values, and hence is maintained betweensuch values. a

The controller 3 is adapted to effect a Well-known series-parallelcontrol for the motors and need not be described in detail. As to thecontroller 20, the contact member 113 is sosubdivided and arranged as tointerrupt the circuit established through the coil 117 of the magnetvalve 12 as each control position is reached. Each successive forwardmovement is thus dependent both upon the limit switches and the positionof the master controller.

The contact member 102 is mounted on an insulating ring 152 that isconnected to the drum of the master controller 81 by a friction clutchor similar connection and is limited in its rotative movement by astationary pin or stop 153 which permits it to move only into engagementwith the fingers 101. The arrangement of parts is such that when themaster switch is moved into its position 1, the friction clutchconnection carries the contact member 102 into engagement with thefingers 101 and the stop 153 holds it in this position as long as themaster switch progresses forwardly, but any backward movement of themaster switch, whether it be from the position 8 or from sameintermediate position, will move the contact member 102 out ofengagement of the fingers and will break the circuit at this point.

From the circuits above traced, it isevident that, as soon as thecircuit is interrupted between the fingers 101, the line switch will beopened and the coils-of the valve 11, 12,

18 and 19 will be deenergized. While'this will produce no -movement ofthe reverser 21, it will throw the drums 3 and to their 01f positions,as hereinbefore pointed out.

Obviously, the circuit connections of the system may be variedconsiderably and the operating head may also be greatly modified as toits structural features and may be employed to operate any form of drumcontroller or regulator, without departing from the spirit and scope ofmy invention, and I, therefore, do not wish my invention limited to thespecific details herein disclosed.

I claim as my invention:

1. In a system of control, the combination with an electric motor, acontroller adapted to occupy a plurality of positions for governing saidmotor, an electrically controlled fluid operated power device foractuating said controller by the continued application of fluidpressure, and a master controller for governin the operation of saidpower device, 0 electro-responsive means dependent upon the motorcurrent for automatically governing a control circuit of said powerdevice.

2. In a system of control, the combination with an electric motor, acontroller adapted to occupy a plurality of positions for governing saidmotor, an electrically controlled fluid operated power device foractuating said controller by the continued application of fluidpressure, and a master controller for governing the operation of saidpower device, of automatic means for governing a control circuit of saidpower de vice in accordance with predetermined conditions of the motorcircuit.

3. In a system of control, the combination with an electric motor, acontroller adapted to occupy a plurality of positions for governing saidmotor, an electrically controlled fluid operated power device foractuating said controller by the continued application of fluidpressure, and a master controller for governing the operation of saidpower device, of a current-limit device having an energizing coil insaid motor circuit, and a switching device in the energizing circuit ofsaid actuating power device for eflecting an automatic acceleration ofsaid motor.

4. In a control system, the combination with an electric motor, acontroller for governing said motor, electro-pneumatic means foractuating said controller by steps by the continued application of fluidpressure, a master controller for manually controlling said actuatingmeans, and an auxiliary control drum associated with said controller forgoverning an energizing circuit of said actuating means, of anelectro-responsive device connected in said motor c1r-' cuit anddependent upon the current traversing said circuit for acting in conuncactuating said controller, and for admitting fluid to both sides ofthe piston to hold said controller stationary, of means responsive tothe current traversing said motor circuit for automatically governingthe operation of said electrically controlled actuating device.

6. In a control system, the combination with an electric motor, acontroller for governing said motor, and an actuator for said controllercomprising a cylinder, a movable piston and electrically controlledvalves at.

each end of said cylinder for admitting an operating fluid to andwithdrawing it from said cylinder, of a manually operated mastercontroller for governing the circuits of said electrically controlledvalves, and a current-limit device for automatically governing theenergizing circuit of one of said valves in accordance withpredetermined conditions of the motor circuit.

7. In a control system, the combination with an electric motor, acontroller for governing the operation of said motor, and an actuatingdevice for said controller comprising a cylinder, a movable piston andelectrically controlled valves governing the admission and release of anoperating fluid at the respective sides of said piston, of.,a manuallyoperated master controller, an auxiliary interlock controller associatedwith the motor controller, and an electroresponsive switching devicedependent upon predetermined conditions of the motor circuit, forconjointly governing the control circuits of said valves.

8. In a control system, the combination gized when it is desired topermit a forward movement of the piston and is. denergized when it isdesired to stop said forward movement, of a current-limit deviceconnected in the motor'circuit and having its switch members adapted toopen and close the energizing circuit of the second electromagnettroller comprising a to automatically effect a step-by-step movement ofsaid main controller in accordance with redetermined current conditions.

9. X control system comprising a drum .controller for governing anelectric motor,

controller for governing an electric motor,

an actuating mechanism for the drum controller comprising a piston and acylinder and valve magnets for governing the admission and release offluid pressure to and from the cylinder, a master controller, meansdependent upon the controller for governing the magnet valves, and alimit switch dependentnpon predetermined conditions in the motor circuitfor interrupting the energization of one of the magnet valves.

11. A control system for an electric motor comprising a drum controller,an operating head therefor comprising a pair of pistons operativelyconnected to the drum, cylinders in which the pistons operate, magnetvalves for controlling the admission and release of,

fluid pressure to and from the cylinders, one of said valves beingnormally open and the other normally closed -when denergized, wherebythe drum controller is biased to its oil position, a master controllerfor governing the suppl of energy to the magnet valves, and a limitswitch dependent upon the current in the motor circuit for delaying thesupply of energy to one of said valves.

12. A control system comprising a drum controller, a control drumoperatively connected to the drum controller, an operating headtherefor, comprising a pair of pistons operatively connected to the drumcontroller and the control drum, cylinders in which the pistons o erate,magnet valves for controlling the a mission of fluid pressure to thecylinders, one of said valves being normally open and the other normallyclosed when deenergized, wherebythe drum controller is biased to its offposition, a master controller cooperating with the control drum forgoverning the magnet valves to produce a step-by-step movement of thedrum controller, and a limit switch dependfor maintaining theaccelerating current becut on the current in the motor circuit forinterrupting the circuit of one of the magnet valves under predeterminedconditions, whereby the advancement of the drum is delayed.

13. In a system of control, the combination with an electric motor, acontroller adapted to occupy a lurality of positions, an electricallcontrolled power device for actuating sai controller, and a mastercontroller for governing the operation of said power device, of aplurality of electro-responsive devices dependent u on differentpredetermined conditions of t e motor circuit for causing said powerdevice to move said controller in op osite directions to govern theoperation 0 said motor and maintain the accelerating current betweenpredetermined limits.

- 14. In a system of control, the combination with an electric motor, aresistor, a controller adapted to occupy a plurality of positions forarranging the circuits of said resistor, an electrically controlledpower device for actuating said controller, and a master controller forgoverning the opera-' tion of said power device, of means dependent upondifferent conditions of the motor circuit for maintaining the motorcurrent during acceleration between predetermined limits.

15. In a system ofocontrol, the combination with an electric motor, aresistor, a controller adapted to occupy a plurality of positions forarranging the circuits of said resistor, an electrically controlledpower device for actuating said controller and a master controller forgoverning the operation of said power device, of a plurality ofcurrent-limit devices for governing the op- 106 eration of said poweractuating device to efle'ct adjustments of said controller in accordancewith different current conditions tween predetermined values.

16. In a system of control, the combination with an electric motor, acontroller adapted to occupy a plurality of positions for governing theoperation of said motor, an electrically controlled power device foractuating said controller, and a master controller for governingtheoperation of said power device, of automatic means for selectivelycausing said power actuating device to move said controller forward orback- 12m ward in accordance with predetermined, conditions of the motorcircuit and to maintain the accelerating current between predeterminedlimits.

17. In a control system, the combination with an electric motor, acontroller for overning the operation of said motor, an an actuatingdevice for said. controller comprising a cylinder, a movable piston andelectrically controlled valves governing the 13m admission and'releaseof an operating fluid at the respective ends of said piston, of aplurality of' ele'ctro-responsive means repectively adapted to governthe energizing circuits of said electrically controlled valves inaccordanc'e'with diflerent predetermined current conditions of the motorcircuit.

18. In a control system, the combination with an electric motor, acontroller governing the operation of said motor, and an actuatingdevice, for said controller comprising a cylinder, a movable piston andelectrically controlled valves governing the admission and release of anoperating fluid at the respective ends of said piston, of a plurality ofcurrent-responsive devices'adjusted for difi'erent motor currents forseverally causing said electrically controlled valves to operate toeflect forward and reverse movements of said piston and controller inaccordance with motor circuit conditions.

19. The combination with an electrical circuit, translating meansconnected thereto, and a regulating device associated with said circuit,of a plurality of electro responsive means for governing the operationof said regulating device in accordance with different load conditionsof said circuit and for maintaining the load between predeterminedlimits.

20. The combination with an electrical circuit, translating meansconnected thereto, and an adjustable resistor associated with saidcircuit, of a plurality of current limit devices respectively responsiveto diiierent amounts of current traversing said circuit for causing saidadjustable resistor to cut in or cut out resistance in accordance withload conditions for maintaining the load between predetermined limits. 7

21. The combination with an electrical circuit, translating means andcontrolling means associated therewith, ofmeans for actuating saidcontrolling means, and automatic electro-responsive means dependent upondifi'erent conditions of load on said translating means for causing saidactuating means to adjust said controlling means to maintain said loadbetween predetermined limits.

22. In a system of control, the combinat1on with an electric motor, acontroller adapted to occupy a plurality of positions for governing theoperation of said motor and an electrically-controlled fluid-operateddevice for actuating said controller and comprlsing a cylinder, amovable piston therein and a plurality of electromagnetic valves forgoverning" the operation of said fluid operated device ofelectro-responsive means dependent upon the motor current forautomatically governing a control circuit of one of said electromagneticvalves.

23. In a control system, the combination with an electric motor, acontroller for governin the operation of said motor and anelectrlcally-controlled fluid-operated device for actuating saidcontroller and comprising a cylinder, a movable piston and a pluralityof valves associated with the respective ends of said cylinder, of meansresponsive to the current traversing said motor for automaticallygoverning the operation of said electrically controlled actuatingdevice.

24. In a control system, the combination with an electric motor, acontroller for governin the operation of said motor and anelectrlcally-controlled fluid-operated device for actuatingsaidcontroller and comprising a cylinder, a movable piston and a pluralityof valves associated with the respective ends of said cylinder, of anauxiliary control drum associated with said controller andelectro-responsive means dependent upon motor current for conjointlygoverning the controlling circuit of one of said valves of saidelectrically controlled actuating device.

25. In a control system, the combination with an electric motor, acontroller for governing the operation of said motor and anelectrically-controlled fluid-operated device for actuating saidcontroller by the continued application of fluid pressure, ofa manuallyoperated master controller, an auxiliary interlock controller associatedwith the motor circuit controller and electro-responsive means dependentupon conditions of the motor circuit for conjointly governing a controlcircuit of said electrically controlled actuating device.

26. The combination with an electric motor, a controller for governingthe operation thereof and an actuator for said controller comprising acylinder, a movable piston, and a plurality of electromagnetic valvesassociated with the opposite ends of said cylinder, of means forgoverning the control circuits of said electromagnetic valves wherebyone of them is continuously energized and the other intermittentlyenergized to eflect step-by-step movements of said piston, and automaticmeans for governing the control circuit of said second electromagneticvalve in accordance with circuit conditions.

27. In a system of control, the combination with an electric motor, acontroller adapted to occupy a plurality of positions for governing theoperation of said motor, and an electrically-controlled power device foractuating said controller, of a master controller 28. In a system ofcontrol, the combination I with an electric motor, a controller adaptedto occupy aplurality ofpositions for governing the operation of saidmotor, and an electrically-controlled power device for actuating saidcontroller and comprising a cylinder, a piston therein and a pluralityof valves associated with the respective ends of said cylinder, of meansfor independently and automatically influencing the action of therespective valves in accordance with different current conditions.

29. In a system of control, the combination with an electric motor, acontroller for governing the operation thereof and anelectrically-controlled fluid-operated mechanism for actuatingsaidcontroller in opposite directions and embodying a plurality ofelectro-magnetically controlled valves, of a pluralityofelectro-responsive relays depend ent upon difi'erent conditions of themotor circuit for independently governing the operation of therespective valves, whereby the direction of movement of the controlleris determined.

30, In a system of control, the combination with an electric motor, acontroller for governing the operation thereof, and anelectrically-controlled fluid-operated mechanism for actuating saidcontroller in opposite directions, of controllable means for governingthe operation of said mechanism, and a plurality of current limitdevices severally responsive to different current'conditions for actingin conjunction with said controllable means for determining thedirection of operation of said controller and maintaining the load uponsaid motor between predetermined limits.

31. In a system of control, the combination with an electric motor, acontroller for gioverning the operation thereof and anelectrically-controlled fluid-operated mechanism for actuating saidcontroller in opposite directions, and comprising an operating cylinder,a movable piston therein and a plurality of electrically-controlledvalves associated with the respective ends of said cylinder, of aplurality of electro-responsive relays dependent upon differentconditions of the motor circuit for severally governing the energizingcircuits of the respective valves.

32. The combination with an electric circuit, a device to be actuatedand an electrically-controlled fluid-operated actuating device thereforcomprising an operating cylinder, a piston therein and a plurality ofelectrically-controlled valves for governing the admission and releaseof operating fluid to and-from said cylinder, of a plurality of meansrespectively responsive to conditions of said electrical circuits forindependently governing the energizing circuits of the respectiveelectrically-controlled valves.

33. The combination with an electric cir cuit, a device to be actuatedand an electrically-controlled fluid-operated actuating de- I ;arrestingthe movement of sai -vice therefor comprising an operating cylentcurrent conditions of the electric circuit andseverally adapted togovern the energizing circuits of the respective electricallycontrolledvalves and to determine the direction of operation of said device to beactuated.

34. In a control system, the combination with an electric motor, acontroller for governing the operation thereof, and an actuating devicefor said controller comprising a cylinder, a movable piston andelectrically-controlled valves associated with said cylinder andadaptedto govern the direction of operatlon of said piston, of a plurality ofcurrent relays adjusted for different current values for severallycausing the respective electrically-controlled valves to operate toeffect forward and reverse movements of said piston in accordance withcircuit conditions.

35. The combination with an electric circuit, translating meansconnected thereto, and means for governing the operation of saidtranslating means, of a plurality of electro-responsive devicesdependent upon different conditions of said electrical circuit forregulating the operation of said translating means and maintaining theload thereof between predetermined limits.

36. In a control system, the combination with an electric motor, acontroller for governing the operation thereof and anelectrically-controlled power-device for actuatating said controller, ofmeans for governing the operation of said power deviceand adapted toeffect movements thereof in opposite directions, electro-responsivemeans cooperating with said governin means for power device underpredetermined conditions, and other electro-responsive means cooperatingwith said governing means and with said firstelectro-res onsive meansfor eflecting a reversal of the irection of movement of said powerdevice under other predetermined circuit conditions.

37. In a control system, the combination with an electric motor, acontroller for governin the operation thereofand an electricaly-controlled power-device for actuating said controller, and comprisingan opcrating cylinder, a piston therein and a plurality of valvesassociated with said cylin' by the motor current for governing theenergizing circuit of one of said valves to arrest movements of saidactuating device in one direction, and another relay responsive todifferent current conditions for governing theenergizing circuit ofanother valve for reversing the direction of operation of v saidactuating device when the motor current exceeds a predetermined abnormalvalue.

38. In a control system, the combination with an electric motor, acontroller for governing the o eration' thereof, anelectricallycontrolled uid-operated actuating device therefor, andcontrollable means for causing said actuating device to move saidcontroller in one direction, of electro-responsive means dependent uponabnormal current conditions for acting in conjunction withsaidcooperating with said electro-magnetic control means to efieotareversal in the direction of operation of said actuator and associatedcontroller under predetermined current conditions.

40. In a control system, the combination with an electric motor, acontroller for governin the operation thereof, and an electricaly-controlled fluid-operated power device for actuatin said controller inopposite directions an comprising a cylinder, a

' piston therein and a-plurality of electricallycontrolled valvesassociated with the respective ends of said cylinder for governing theadmission and release of operating fluid to and from said cylinder, of amaster controller for governin the operation of said valves, a currentre ay for governing the energizing circuit of one of said valves and asecond current relay responsive to difi'erent current conditions forgoverning the energizing circuit of the other of said valves whereby thedirection of operation of said actuating device is determined.

41. In a system of control, the combination with an electric translatingdevice and a regulating device therefor comprising a fluid container,movable means contained therein and electrically controlled valvesdisposed at the respective ends of said fluid container, ofelectro-responsive means for governing the operation of at least one ofsaid electrically controlled valves in accordance with the loadconditions upon said translating device.

42. The combination with an electric cir- 4 cuit, and electricallycontrolled fluid-actuated means for varying the electrical conditions ofsaid circuit, said means embodying a cylinder, a movable piston andelectrically controlled valves at the respective ends of said cylinder,of automatic means responsive to electrical conditions of said circuitfor governing the operation of one of said elec trically operatedvalves.

In testimony whereof, I have hereunto subscribed my name this 17th dayof October 1913.

ARTHUR J. HALL.

